Natural experiments can provide valuable insights into economic questions.
安全不是产品,而是一种能力。
小说是一面反映社会的镜子,包括所有的光明和阴影。
You have to fight through some bad days to earn the best days of your life
On pricing: "There are two kinds of companies, those that work to try to charge more and those that work to charge less. We will be the second."